Bootloader Resets Once Right After Program

[Matt22]

I am running SDK 15.2 on an nRF52840. I have programmed my secure dfu bootloader, application, settings.hex, and softdevice via jtag. During the first run after programming the bootloader runs, resets, runs, and then successfully executes my application. This reset only occurs on the first run after programming the bootloader. I am trying to understand why this reset is occurring. I was thinking it had something to do with the master boot record not being initialized. Either that or possibly something with my settings.hex. I think settings.hex is less likely but here how I am creating it.

nrfutil settings generate --family NRF52840 --application app.hex --application-version 1 --bootloader-version 1 --bl-settings-version 1 settings.hex

[AbhinavEV]

Hi Matt,

Could you please explain me how to program bootloader.hex, application.hex, settings.hex and softdevice simultaneously using JTAG. Are you able to update the application.hex file again and again without disturbing bootloader.hex. 

I am trying to develop an application and I am stuck here.

Thanks in advance.

[Matt22]

There are plenty of tools to program them, nrfjprog, nrfgo studio, or just in Segger Embedded Studio as additional load files when you debug. The application can be reloaded without changing the bootloader and softdevice but if you want to go this route you probably should regenerate and program the settings.hex as it contains a CRC of the application which would change.